The present invention relates generally to a pull-on disposable wearing article and particularly to such wearing articles suitable for a pull-on incontinence diaper, a pull-on disposable diaper for infants, a disposable training pant for babies, and particularly for a pull-on disposable incontinence diaper.
The conventional pull-on disposable wearing article has often been focused to meet the demand for good fitness of the article when the article is put on the wearer's body and consequentially a front waist region as well as a rear waist region has been constructed to be elastically extensible/contractible overall in a circumferential direction. For example, Japanese Patent Publication No. 3581373 (hereinafter referred to as “REFERENCE 1”) discloses a pull-on disposable diaper wherein the front and rear waist regions include elastic members sandwiched between inner and outer sheets thereof.
Japanese Unexamined Patent Application Publication Nos. 1987-231005, 1987-243806 and 1987-243807 (hereinafter referred to as “REFERENCE 2”, “REFERENCE 3” and “REFERENCE 4”, respectively) disclose disposable absorbent pants having an absorbent core and a crotch region provided along bottoms of respective concavely curving side edges with relatively wide elastic members.
Japanese Patent Publication No. 3616077 (hereinafter referred to as “REFERENCE 5”) discloses a disposable diaper having an absorbent layer provided with at least three grooves extending from a crotch region into front and rear waist regions.
According to the disclosure of REFERENCE 1, the inner and outer sheets of the front and rear waist regions are formed with gathers as the elastic members contract. The gathers formed on the outer surfaces of the front and rear waist regions are not only undesirable for appearance of the diaper but also apt to catch on something, causing a state of the article put on the wearer's body to be disordered or material of the waist regions to be damaged.
According to the disclosure of REFERENCES 2-4, any specific technical significance of the relatively wide elastic members attached to the crotch region along the bottoms of the concavely curving side edges is not referred to. Particularly, no technical significance of the correlation between the relatively wide elastic members and the absorbing effect can be found in the disclosure. In view of this, use of such relatively wide elastic members is not considered to be based on any technical significance.
According to the disclosure of REFERENCE 5, a central region of a flat absorbent layer is deformed along the grooves to present a W-shaped cross-section while transversely opposite side edges are bent downward as the diaper is put on the wearer's body. The side edges bent downward in this manner come in close contact with the inner sides of the wearer's thighs. In general, the absorbent layer has a stiffness higher than those of the remaining components of the diaper, and the side edges of such stiff absorbent layer being bent downward and coming in close contact with the inner sides of the wearer's thighs inevitably causes the wearer to experience somewhat discomfort feeling. Furthermore, the W-shaped cross-section appearing when this absorbent layer is deformed presents many folds, i.e., crests and troughs since the side edges also are folded downward. Therefore, it is not ensured that the absorbent layer is reliably folded or deformed in the predetermined shape.